Pre-engraved projectiles and gun for firing same



Sept 1957 FQR. SIMPSON 0 PRE-ENGRAVED PROJECTILES AND GUNWFDR- FIRING SAME Filed June 14. 19.51 4 Shets-Sheet 1 I r Ill v II I Sept. 3, 1957 F. R. SIMPSON PRE-ENGRAVED' PROJECTILES AND GUN FOR FIRING SAME Filed Juhe 14. 1951 4 Sheets-Shee t 2 Sept. 3, 1957 sm so 2,804,806

FREE-ENGRAVED PROJECTILES AND GUN FOR FIRING SAME Filed June 14, 1951 4 Sheets-Sheet 3 FIJ'IK R- 5 imps cm.

pt. 7 F. R. SIMPSON 2,804,806

PRES-ENGRAVED PROJECTILES AND GUN FOR FIRING SAME Filed June 14, 1951 4 Sheets-Sheet 4:

. arwa wfm Frank H-51' flp5un Unite Stes atent fiice 2,804,805 Patented Sept. 3, 1957 PRE-ENGRAVED PRGJECTILES AND GUN FOR FmlN G SAME Frank R. Simpson, Upper Darby, Pa., assignor to the United States of America as represented by the Secretary of the Army Application June 14, 1951, Serial No. 231,493

9 Claims. (CI. 89-33) This invention relates to pre-engraved ammunition for use with rifle guns. In the usual fixed round of ammunition, the projectile has a relatively narrow soft metal driving band extending thereabout and rigidly fixed therewith. This band has an outer diameter substantially equal to twice the radial distance from the bore axis of the barrel to the bottom of the grooves of the rifling so that as the projectile is driven along the barrel, its driving band is scored or engraved by the rifling of the barrel and the projectile is constrained to follow the helical rifling and thereby to acquire the necessary stabilizing spin.

The present invention contemplates the use of fixed ammunition or cartridges the projectiles or bullets whereof are pre-engraved, that is, provided with helical splines which initially fit smoothly between the lands of the barrel rifling and create a minimum of friction with the barrel surface, while etiecting a substantially gas-tight relation therewith. In an obvious manner, such projectiles reduce wear and friction, increase muzzle velocity for the same propelling charge and increase the useful life of the barrel.

While having great advantages, the use of pre-engraved projectiles in rapid-fire guns, requires that each cartridge be in such a rotational position at the instant it is rammed into the breech, that the splines on its bullet will register or mesh accurately with the grooves of the rifling. Otherwise jamming and interference may occur between the engraved projectile and lands of the rifling and impair the operation of the gun.

The foregoing considerations make it desirable that each cartridge be fed to the breech of the gun, with its projectile positively positioned and held in the aforesaid rotational position; and in order to effect this function, I propose to form the base of each cartridge case with indexing means such as radially oliset notch, groove or lug which will cooperate with the belt or clip as well as with the loading mechanism of the gun, to feed each cartridge into the gun and load it into the breech, in proper rotational position. Then when each cartridge is assembled with its pre-engraved bullet so that its splines bear a certain or predetermined angular relation with the aforesaid indexing means of the cartridge case, proper loading of each cartridge is assured and the benefits and advantages of pre-engraved ammunition are fully exploited.

It is the object of the present invention to provide a clip particularly adapted to hold several rounds of ammunition in side-by-side contacting relation so that each.

Another object is to provide the combination of a clip and plurality of rounds of ammunition which will enable the benefits of pre-engraved ammunition to be realized to the fullest extent.

A still further object is to provide the loading mechanism and tray of a 40 mm. automatic gun, with means cooperating with the cartridge generally and particularly with the aforesaid indexing means of its case, to positively control the rotational position of the cartridge from the time it leaves its clip until it is rammed into the breech with the splines upon its bullet in proper meshing relation with the rifling of the barrel.

Another object is to provide a system or mechanism wherein the rotational position of the cartridge and its indexing means is positively controlled from the time it is loaded into its clip until rammed into the breech of the gun.

Other objects and advantages will be apparent after a study of the following detailed description in connection with the accompanying drawing.

In the drawing:

Figure 1 is a side elevation of a clip holding four cartridges.

Figure 2 is an end elevation of the clip of Figure 1 with one cartridge removed.

Figure 3 is a cross-section to an enlargedrscale, taken upon the line 33, Figure 2.

Figure 4 is a cross-sectional view of a clip and cartridge in the loader of a 40 mm. automatic gun, taken upon line.44, Figurell, and showing the way in which the cartridges are released from the clip asthey .are fed downwardly with respect to the loader.

Figure 5 is an end view of a cartridge provided with one type of indexing means.

Figure 6 is an end view of a cartridge provided with a second type of indexing means.

Figure 7 is a sectional view, taken in a vertical axial plane, of a 40 mm. automatic gun and showing portions of the loader and cartridge tray, with means to positively guide the lowermost, cartridge into the tray in fixed predetermined rotational position.

Figure 8 is a perspective view of the loading tray showing a longitudinal guide rail thereon for guiding the cartridges in axial translation only, during ramming.

Figure 9 is an end View of the loading tray and a portion of the loader, showing the guide rail in end elevation and a latch in the loader which may be used, if desired, to hold each cartridge with its indexing notch fitting over and about the guide rail during the initial stage of ramming.

Figure 10 is a perspective view of the rear portions of the automatic loader with a clip of ammunition therein, together with a portion of the loading tray.

Figure 11 is a sectional view taken in a vertical plane indicated by line 11-11, Figure 10.

Figure 12 is a perspective view showing the feed rollers and indexing means of a standard 40 mm. automatic gun. Figure 13 is a vertical section through a portion of the gun showing a special attachment for guiding a round of ammunition in fixed rotational position from the time it leaves the clip until it is deposited by the feed rollers upon the loading tray. In this figure a round has just begun its downward movement from clip to tray.

Figure 14 is a view corresponding .to Figure 13 but showing how the attachment is released from the round in response to depositing of the round upon the tray.

Figure 15 is a view corresponding to Figures 13 and 14 but showing the position of the attachment forming a part of the invention when an empty cartridge case is ejected in the direction of the arrow, Figure 16 is an exploded View of the detent and spring forming portions of the aforesaid attachment.

Fig. 17 is a front elevation of the latch mechanism by which each cartridge is guided, without turning, from the magazine to theloadi'ng tray, and

Fig. 18 is a rear elevation of the same mechanism shown in Fig. 17.

Referring in detail to the drawing,'1 identifies in -g'eneral a clip adapted to hold'four rounds of cartridges and comprising a channel element 2 generally lJvs'h'aped in cross-section and having four arcuate notches ;in its upstanding sides, as indicated at 3, Figure2. As shown at 4, upon Figure .3, one side wall of .the'channel element is oifset inwardly toward the other side wall, whereby to form a rim or ledge of a minimum depth substantially equal to the width of radial dimension (or the flange of the cartridge head. As seen in'Figure l, theclip is. slightly curved longitudinally on jradii corres'p'on'din'gt'o' those of the automatic loaderguides, whereby adjacent rounds remain in contact at their rims as well as at a point near the for'ward ends or the cartridge cases. See Figure '7.

A-t-each of four .pointsalong its length, corresponding to its four'most narrow dimensions, the ;clip is provided with a non-circular rod5 .s'lidably mounted for longitudinal movement and urged to the right, as viewed in Figure 3, by a spring 6 acting betweenthe'wall .of the clip and 'a'fiange 5a fixed to the rod. In the position shown, the inner end .of.the.rod,.projects from :clip so that, whenfo'rce'd inwardly against Itheactionzof. spring 6 a clamp member] .rigidlyattached tothe-other-end of the ma, moved rearwardlyaway fromthe .clip to release the, rim of the cartridge .caseLC. W

. The foregoing described construction is. standard equipment for the automatic loader of theArmys 40 mm. gun and ,per se, forms no partof the present invention.

.When this clip is fused with standard ammunition, there is vno necessity to locate the rounds within the clip in any particular rotational position. Each round is loaded The backing plate is formed with aforwardly andvertically extending ridge 15a which engages theh'eads of the cartridge within the feeding mechanismand spaces them forwardly a distance sufiicient to provide a space enabling clamp members 7 to 'be moved rearwardly to release the cartridges from the clip as they are moved downwardly in the loader. This release is effected by a cam plate 18 secured to or integral with, side 17, as shown in Figures 4 and 11, and having a cam surface 18a, Figure 11, which engages the projecting ends ofclip pins 5 as the clip and its cartridges slide downwardlyin the loader, and forces the clamp members 7 rearwardly to thereby release the lower cartridges from the clip.

3 In this way, as feed mechanism 14 is operated, in response to counterrecoil movement of the barrel and loading tray, to move thecartridges one step downwardly, the lowermost'cartridge is forced between the feed rollers 21and 22, shown at Figure 12, and subsequently described. The

' feed mechanism of the gun, as just described is of standsimply bymanual pressureon the-end of pin- 5, insertion of the round into its notches, and releaseof the .pin. The rounds are thus held in theposition shown upon Figures 1 to;3, and, together withthe-clip, are slipped downwardly between'the front and rear. guides of the automatic loader for firing. 7 I

Where pre-engraved ammunition isto be used, I propose-to load each round into its clip in the same fixed predetermined rotational position and to include in the automatic loader of the gun itself, means by which the aforesaidrotational position of each round is maintained until it .is. rammed into the breech. For this purpose, I provide a chordal channel or groove '8 -in the head or eachcartridge. In addition, the circular groovein the head ofeac'hcartridge is provided with a pair of pins Q and 10 spaced linearly a distance equal to the width of the clampmembers 7 and in a direction parallel to .grooves orchanne'ls 8, as will be clear frominspection oil-Figures 2 and '5. The pins have aprojectinglengthsubstantially equal to the depth .of'thepircular groove '1'1 in .which they are positioned so that their ends are flush with .the head ofthe cartridge cases. a

- 'Figure's2, 3, 4, and J11 show that the end of each clamp member. .7is turned inwardly to form a lug fitting between. thetwo pins .and that when the rounds are so positionediin the clip, the .grooves' 8 are in alignment in the longitudinal direction of the clip, that-is, the direc-' tion of movement of the "clip and cartridges withinthe automaticfloader of th'e gun. This automatic loader in c ludes,aforward guide 12, Figure 7, having achannel to receive andg'uide the noses ofthe splined bullets-B, a rear guide 13fto receive:and,gu ide, the heads;of,the cartridge'icases, and automatic feed mechanism generally indicated at .14, but'not showniin detail. ,In -a-manner subsequently described, thisffeed mechanism .is operated by movement of the loading-tray in recoil and counten recoil. The forward guide :12 is generally ran ,arcuate upstanding channeled member flaring at tits top. and adapted tofg'u'ide thegnoses .of thexbullets in vidownfvard ar'd co nstruction. In addition, I provide a strip orlrail 19 fixed to plate 15, spaced from and parallel'to ridge 15a and so positioned and of a length suflicient toengag'e within the aligned grooves 8 in the cartridge heads during their downward travel in the loader and until the .cartridges, in sequence are gripped by the heads of the rammer levers. By this provision the cartridges are maintained-in fixed rotational positions from thetime they are loaded into the gun with their. clip until they are,

. deposited in sequence upon thelloading tray 20.

In the ,gun described, the loading'tray is rigidly secured to the breech ring and projects rearwardly therefrom and recoils as a unit therewith; This tray hascam grooves 42 and 43 .(Figure 8) along its right and left sides, and

as the barrel, breech ring and rtray move forwardly in counterrecoil, feed rods having rollers at their lowerends riding in the respective cam grooves, are moved down wardly by the grooves to move all cartridges in the loader and their clip, down one step after the empty case of the cartridge previously-fired has been ejected. A pair 'of cross section (see.Figure ,12) are mounted in side-by-side' laterally-shaped, -longitudinally-extending feed rollers 21 and 22 are carried by the loading mechanism for positive supportof the lowermost cartridgein the loader. These rollers which are in the shape of fourepointed stars in fore and aftrelation immediately below the lowermost cartridge -in the loader. Each rod is mounted at its forward ends for pivotal movement about a respective axis asi-ndicated at 25 and 26, which axes are parallel, vertical and normal to the axis of rotation of the rollers, whereby the separation of the rollers may vary. This separation.

is such that thelatter are yieldinglyheld in ,position co'n jointly forming an upwardly-facing semi-circular channel into which the lowermost cartridge is forced bythefced mechanism; This movement forces the feed rollers and index wheels to rotate one-quarter rotation and insures that but one cartridge may-be deposited upon the feed trayffor each reciprocation thereof in recoil andcounterrecoil.

grip a cartridge as it'passes therebetweem The-rollers are normally locked in position by catch heads 31-and 32 flflunteld upon respective spindles ,.33.andg34. During The pivotal mounting of the feed roller shafts enables --the'rollers to separate slightly and continuouslycounterrecoil, when the cartridges are being depressed by the feed mechanism to deposit the lowermost cartridge upon the tray, the loading tray pawls 35 and 36, Figure 8, engage and rotate the catch heads. This action releases the feed rollers and permits them to be revolved by the cartridge in the manner previously described. When the cartridge has passed between the feed rollers and the rollers have rotated one-quarter turn, the catch heads are returned to their normal positions by torsion springs such as 37, shown in Figure 12 for catch 31. This again locks the rollers in position until released by the next reciprocation of the tray.

The upper ends of the rammer levers are indicated at 38 and 39, Figure 8. These levers are independently pivoted on a common rammer rod (not shown). The rammer levers project upwardly through respective cam slots 40 and 41 in the loading tray. These slots have oppositely-disposed riser portions 40a and 41a each connecting straight parallel portions at difierent transverse distances from the central longitudinal axis of the tray. As previously described the automatic feed mechanism is operated by rollers not shown, riding in respective cam slots or channels 42 and 43 formed upon the tray 2%. See Figures 7 and 8. These slots have riser portions 42a and 43a, each connecting two parallel sections, such as 4211 and 420 and act to raise the feed pawls during recoil and then to lower them at the proper time during counterrecoil to eifect the aforementioned downward feeding of the cartridges and to move the lowermost cartridge between feed rollers 21 and 22, and to deposit it upon the tray.

Forward movement of the tray with the gun barrel in counterrecoil acts to tension a rammer spring, not shown, which then acts to urge the rammer arms forwardly in their slots 41' and 41. The active or riser portions 40a and 41a of slots 40 and 41 are so positioned longitudinally of the tray, with respect to the active portions 42a and 43a of channels 42 and 43, that the upper ends of rammer levers 38 and 39 are moved inwardly toward each other at the instant the feed mechanism is operated to deposit a cartridge upon the tray. At that instant, of course, the rim or head of the deposited cartridge is coplanar with the rammer levers so that as the rammer levers move toward each other they grip the head of the cartridge between them. At this time the rammer levers are latched in rearwardmost position while the gun and tray are moving in counterrecoil toward battery position. The breechblock of the gun is, of course, fully open.

As the barrel and tray near battery position loading tray pawls 35 and 36 trip the catch holding the rammer lever and arms 33 and 39 in retracted position and the now-compressed rammer spring throws the arms and the cartridge gripped between them, forwardly at extremely high speed. As the arms move forwardly past the riser or active portion 49a of their slots, they are separated. The cartridge is released and moves forward under its own momentum into the breech. Movement of the cartridge into the breech releases the breechblock in a well-known manner which, on closing, fires the gun when in automatic fire.

In view of the fact that there might otherwise be a short period dter the cartridge leaves guide strip 19 until it is gripped by rammer levers 38, 39 and otherwise held in rotational position upon the tray, I have provided a detent mechanism which, in effect, forms a continuation of strip 19 and moves downardly with the cartridge until the latter is gripped by the rammer levers.

This detent or guide mechanism comprises a plunger element 44 having a head 44a slidably fitting a bore 45 formed in the loader frame. The plunger is limited to reciprocation only and is urged upwardly by a coil spring 46 into the normal position shown upon Figure 15. The plunger element has a forwardly-offset end portion 4412. This portion has its forward vertical edge so shaped and normally positioned to form a continuation of guide strip 19, as will be noted from Figure 15, whereby the rotational position of the lowermost cartridge is controlled only by the detent or guide mechanism by reason of its engagement within the indexing groove in the cartridge head.

A latch generally identified by the numeral 47 in Fig ures 13, 14 and 15, and shown in greater detail upon Figures 16, 17 and 18, is carried by the lower end of offset portion 44b. The latch may conveniently have the general form shown upon Figure 16, pivoted to the plunger on a transverse axis defined by aligned holes 48 and urged into clockwise rotation as viewed in Figures 13, 14 and 15, by a leaf spring 49 having forwardly offset lateral projections 49a. These projections engage the respective side walls of latch 47 and urge the same into a rotation position wherein the nose portion 47a projects forwardly into a position to be engaged by the rim of the lowermost cartridge, as shown by Figure 15. Rotation of the latch is limited to the position shown on Figures 13 and 15 by engagement between the edges of projections 4712, with the ends of a pin 50 having a press fit within a transverse bore in plunger 44. The base of the latch has rearwardly-projecting arms 47c, Figure 16, to and between which there is secured an anti-friction block 51, Figures 17 and 18. This block projects below the lower edges of the arms 47c and, being rearwardly offset from the axis of holes 48 pivots the latch counterclockwise when moved into contact with the surface of loading tray 20, as will be clear from inspection of Figure 14.

By the construction just described, as the lowermost cartridge is forced downwardly by the feed mechanism, in the manner previously described, its engagement with nose 48a of latch 47, causes the entire plunger element to move downwardly as a unit with the cartridge until, when block 51 strikes the loading tray, the latch 47 is pivoted to remove nose 47a from the rim of the cartridge. Whereupon, spring 46 causes the entire plunger element to snap back into the position shown in Figure 15 wherein the forward edge of portion 44]) engages within the indexing groove 8 of the next cartridge.

It will thus be seen that the construction just described maintains each cartridge, as it is fed downwardly from the feed mechanism to the loading tray, in fixed rotational position and acts to maintain such position until the cartridge rests upon the tray and is engaged by the rammer arms as previously described.

It is contemplated that the rammer levers alone may be sufiicient to maintain the cartridge in proper rotational position upon the loading tray until it is released therefrom by the action of the active or riser portions 40a and 41a of slots 40 and 41, and thrown forwardly at high velocity into the breech. However in addition to the gripping action of the rammer levers, I provide a guide rail 52, rigidly secured to the loading tray longitudinally thereof and so positioned and shaped as to engage within the notch in the rim of the cartridge case, such as 3a, Figure 5. This guide rail is in the same longitudinal vertical plane as guide strip 19 so that, as the lowermost cartridge in the loader or magazine is guided downwardly without rotation, the notch in the rim of its head fits over and engages the rail. This acts to prevent angular movement of the cartridge during the instant its rim is gripped by the rammer levers. As the guide rail extends throughout the length of the loading tray, as shown upon Figure 8, the correct angular position of the cartridge is maintained after it has been released by portions 40a and 41a of the cam slots as the rammer rod and its arms are moved forwardly relatively to the tray. The cartridge is thus positively guided to prevent its rotationor angular movement about its longitudinal axis from the time it is loaded into the magazine or loader, until it is rammed into the breech with the splines of its bullet in proper registration with the rea terminals of the rifiing grooves of the barrel.

Due to the high speed with which the cartridge is rammedintothe breech, and with which the empty case is !thrown rearwardly by therextraetors, it is .desirable to ;provide some means for exerting a jdownward force upon the cartridge during its forward movement with and also relativelytogthe tray, as'welltas duringtherearward movement :of the empty cartridge case. For this purpose, I have provided a yielding r rfiexible- .detent 53, Figures? and 9. This detent is pivoted-at.oneend as indicated at '4, Figure 9, on a longitudinal axis and'is urged into clockwise :rotationgas viewed,:-by a .sprin g SS. The detent'is positioned ion-the automatic loader just beneath and 5 forwardly of thefront cartridge guide 12 so that the nose of each cartridge just'clears the same as it is fetlidownwardlyonto the tray. Thedetent-is limited "in downwar'd pivotal movement, by any' suitable stop mechanism, not shown, to :substantially the position showmuponlFigure9. Hence, as the cartridge is moved forwardlyg-the nose of 'its" bullet passes beneath. the detent and pivotsihe same upwardly-against the force of spring 55. The detent thus exerts a -downward'forceuponrthe cartridge which prevents it from bouncing upon the tray. As theemptycartridge case is thrown rearwardly by the ext'ractors, its rim again cams detents 53 slightly upwardly whereby the empty-case isheldwiththe notch infits headfitti-ngover rail'52-so that'the correct rotational positi0n of the 'empty case is-maintained until it is clear of I the gun. a

When cartridges having index means of-the typeshown upon Figure 6 are used, it is contemplated that the loading tray'will 'be provided with twospaced parallel guide railsrsimilar to rail 52,.each-positioned to fit a respective notch 8b and 8c in the cartridge rim, thusaifording added protection against axial rotation of the-cartridge and empty case.

I havethus provided a complete system particularly adapte'd' 'forthe-automatic gun described wherein preengraved-ammunition may be used without danger of jamming and the great benefits and advantages thereof utilized :an'd explc-ited to the fullest extent. Any minor rotational misalignment between the cartridge and the rifiing: at the breech will be corrected by the tapered or pointedends of the splines upon-the bullet, as-indieated upon 'Figure 7 and as described in my copending application Serial No. 227,035, filed May 18, 1951, where- V in-is 'disclosed-and claimed an apparatus for assemblying pro-engraved bullets in proper predetermined angular relation with respectto' the indexing slot andfor notches upon the head'of the cartridge case.

EInI the claims, theterm indexing means comprehends the' slotj8 or8' as shown in Figures '5 and 6 respectively,

and-at least one-notch in the cartridge rim, such as 8a, Figure 5, or=8b or 80, Figure 6 The .term meshing relation means an angular or rotational position of the cartridge'with respect to the breech .wherein the splines upon the-preen'graved projectile of the cartridge will freely enter between 'thelands of the rifiing of the barrel at 'the breech-end thereof, by a straight axial translation of the cartridge and without anysubstantial rotation thereof. By' 'raming position is meant a position of the cartridge rearWardIy of the breech and in axial align' ment with the bore ofthe gun whereby loading into the breechmay be effected. by a pu'reaxial translation of the cartridge. The term" transverse as applied to the groove or channel in the-head of the cartridge case, means at right angles to the central longitudinal axis of the cartridge.

" -Havingnow fully disclosed the invention, what I claim and desire to secure by Letters-Patent is: --l.fIn an automatic cannon-for'firing cartridges each having a splined projectile and anotched casing head rim-in' -predetermined rotational relation with the splines by and inzresponseztoreciprocation of said. tray for receiving-and depositing in succession on saidtray, a plurality of cartridges in 'saidzloa'ding 'means, .said loading :means including .mechanism depositing reach cartridge on said tray with its notch fittingrover said guide rail, whereby each .cartridgeis limited .to axial translation only in-loadingmovementiin andlalongsaidtray. a

.2. In .an automatic r gun :for i firing cartridges each having a-pre-engraved projectile, -a transversegroove in its casing .head, :and a notch in the rim of said head, said projectile, groove and notch'being in predetermined fixed angular relation about the axis of the cartridge, a load ing.- tray fixed tothe' breech of said gun in alignment therewith and reciprocating therewith in recoil and counterrecoil, a guide-rail fixedly carried-bysaid tray and extending longitudinally in and along thesame, an automatic feeding mechanism forminga part of said gunand adapted to receive and guidea plurality of cartridges in vertically stacked' -rel ation, means operated by and in response to each reciprocation of said tray to feed the cartridge downwardly step-by-step and to deposit the lowermost one of the cartridges insaid feeding mechanism onto said tray, aguide strip carried by said feeding mech anism and constructed and arranged to simultaneously engage within the grooves in all cartridges therein to limit the same'to vertical translation, said guide strip comprising -a fixed upper portion and a vertically movable'lower portion, means mounting said lower portion for longitudinal vertical translation only, a'latch carried by said lower portionfor releasably engaging said lowermost cartridge and moving said'lower portion only as a unit therewith adjacent said tray, said latch being released from the cartridge by and in response to engagement with said tray, means yieldingly urging said lower portion into uppermost position,.each cartridge being ,depos'itedon said tray with its notch fitting over said guide rail, and means engaging each cartridge on said tray and translating the same'longitudinally on andialong said rail into the breechof the gun, whereby each cartridge is rammed with'the splines of its projectile in meshing relation with the rifiing of the barrel of the gun.

3. The combination with an automatic gun for firing pre-engrave'd projectilesand having a loading trayand a feeding mechanism for holding and feeding a plurality of vertically stacked cartridges in succession onto saidtray for. loading therefrom into the breech of the gun, each cartridge having indexing means fixed in its casing-head and a pre-engraved projectile having the forward ends of its lands in predetermined angular relation with said indexing means, of means associated with said feeding mechanism and engaging said indexing means for feed ing each cartridge in succession onto said tray in predetermined fixed angular position, and means associated with said tray and engaging with the indexing means of a cartridge therein, for maintaining said cartridge in its aforesaid angular position during its loading movement in and alongsaid tray into the breech of the gun, whereby the forward ends of the lands of'each cartridge mesh with the breechward end of the rifiing of the gun.

4. The combination with an automatic gun for firing pro-engraved projectiles and having a loadingtray'and feeding mechanism for feeding a plurality of cartridges in succession onto said trayfor loading therefrom into the breech of the gun, each cartridge having a pre-en" graved projectile and indexing means including'a trans verse groove in its casinghead in predetermined fixed rotational relation with the forward ends of the lands of sa1d projectile, of guide means forming a portion of said feeding mechanism and engaging within thegrooves of each ofa plurality of vertically stacked cartridges therein to gulde the same. onto said, tray in'succession, each with its projectile in fixed predetermined angular relation with the breechward ,end of the rifiing of the gun, anda guide rail carried ,by said tray and extending longitudinally thereof, sa1d gui'de rail and indexing means interengagi Iting to maintain each cartridge in said fixed angular relation during loading movement thereof in and along said tray into the breech of the gun, whereby each cartridge is loaded in translational movement only.

5. In an automatic gun for firing pre-engraved projectiles and having a loading tray movable as a unit with the barrel of the gun and for supporting cartridges for movement in succession into the breech of the barrel, an automatic feeding mechanism for depositing cartridges in a transverse direction from a vertically stacked position in said loading mechanism, in succession onto said tray, each cartridge having a pro-engraved projectile, a transverse groove in its casing head and a notch in its rim, said projectile, groove, and notch being in a predetermined fixed rotational relation, a guide rail carried by said feeding mechanism and simultaneously engaging the grooves of a plurality of cartridges held therein whereby each cartridge is guided for transverse motion in succession onto said tray with its projectile in predetermined angular relation with the breechward end of the rifling of the barrel of the gun, and a guide rail fixed in said tray longitudinally thereof said guide rail engaging the notch in each cartridge case as the latter is deposited thereon, to maintain each cartridge in said angular relation during its loading movement in and along said tray into the breech of the gun, whereby the forward ends of the lands of the projectile of each cartridge enter freely between the rearward ends of the lands of the barrel.

6. In an automatic cannon for firing cartridges, each having a pre'engraved projectile and a transverse groove in its casing head, a feeding mechanism comprising vertical guide means receiving and holding a plurality of cartridges in vertically stacked relation and guiding the same for movement successively into position for ramming into the breech of the cannon, said guide means including a vertically disposed rail, fixed with said feeding mechanism and constructed and arranged to simultaneously and slidably fit the grooves in the casing heads of all cartridges in the feeding mechanism, said rail including a lower extension, means mounting said lower extension for vertical reciprocation only, releasable latch means carried by said extension and engageable with a cartridge held by said extension to cause said cartridge and extension to move downwardly as a unit, and resilient means urging said extension into upward movement.

7. An automatic cannon as recited in claim 6, and means releasing said latch means in response to a predetermined downward movement of said extension.

8. In an automatic cannon for firing cartridges each having a splined projectile and a case provided with a transverse groove in its head, a feeding mechanism comprising vertical guide means receiving and holding a plurality of cartridges in vertically stacked relation and guiding the same for movement successively into ramming position, said guide means including a normally vertical guide rail and constructed and arranged to simultaneously engage the transverse grooves of all cartridges in the feeding mechanism, said rail comprising an upper fixed section and a lower section forming a continuation of said upper section and engaging within the groove of the lowermost cartridge only in said feeding mechanism, means mounting said lower section for vertical longitudinal translation only, releasable latch means carried by said lower section for engagement with the lowermost cartridge, whereby said lowermost cartridge and lower section move downwardly as a unit, a loading tray, means loading said lowermost cartridge onto said tray, means releasing said latch means in response to engagement thereof with said tray, and spring means urging said lower rail section upwardly into position forming a continuation of said upper rail section.

9. An automatic cannon as recited in claim 8, and a longitudinally-extending rail fixed in said tray and engageable in a notch in the head of each cartridge as the latter is loaded downwardly thereupon.

References Cited in the file of this patent UNITED STATES PATENTS 683,384 Cole Sept. 24, 1901 701,798 Cole June 3, 1902 1,777,519 Flowers Oct. 7, 1930 2,354,499 Calhoun July 25, 1944 2,356,413 Leighton Aug. 22, 1944 2,424,964 Bowser Aug. 5, 1947 2,456,011 Musser Dec. 14, 1948 2,529,504 Kroeger Nov. 14, 1950 2,541,530 Meyer Feb. 13, 1951 2,541,616 Sasser Feb. 13, 1951 

